Antal's 20mm Deck Ring is made of anodized aluminum and has smooth surfaces to minimize friction. It is ideal for use with control lines and running rigging and can be used as a low-friction fairlead or as an attachment point for rings and loops. It has a 25/32 in. (20mm) aperture and measures 2 21/64 in. long x 1 35/64 in. high x 3/4 in. wide (59mm x 39mm x 19mm). It weighs 1.55 oz (44g).